1. Oil steady: Crude futures have jumped by around 2.5% overnight to above $28 a barrel. The recovery follows a fall of more than 6% on Tuesday because of fears that a global supply glut may persist for longer than expected. The U.S. government will update its weekly crude oil inventories data at 10:30 am ET.

2. Banks bounce back: European banking stocks are rebounding after a miserable start to the year. Deutsche Bank(DB) is leading the way -- its shares jumped 12% after CEO John Cryan said Tuesday the bank was "rock solid." Sentiment was helped by media reports that it might buy back some debt -- a trade that could make the bank money if it pays less than face value for the bonds. Deutsche declined to comment on the reports.

3. Other movers -- Disney, Arm: Disney(DIS) shares were down as much as 6% during extended trading after an earnings update, even though it revealed its ESPN television network gained subscribers and "Star Wars" gave the studio record box office totals. Analysts were expecting better. Shares in chip designer Arm Holdings(ARMH) are down 2% in London after reporting earnings in line with expectations. The smartphone supplier has suffered recently along with Apple(AAPL) shares.

4. Fed Speak: Federal Reserve Chair Janet Yellen starts two days of testimony on Capitol Hill. Markets are looking for clues as to whether the Fed will raise interest rates again this year.

5. Earnings: Companies reporting ahead of the open include Humana(HUM) and Time Warner(TWX), CNN's parent company. Among the companies that investors will hear from this afternoon are Cisco(CSCO), Prudential(PRU), Whole Foods(WFM), Tesla(TSLA) and Twitter(TWTR).

6. Market overview:European markets are jumping by about 2% in trading on the back of the bank rally. Asia Pacific markets ended lower, with the Nikkei down 2.3% to its lowest level since October 2014.